Finding child processes recursive in nodejs without external dependencies

findprocs.js

#!/usr/bin/env node
const ChildProcess = require('child_process')


function findChildren(pid) {
    const pgrep = ChildProcess.spawnSync('pgrep', ['-P', pid])

    // Probably segfault..
    // Happens on linux at least when there is no child
    if(pgrep.status === null) {
        return []
    }

    const pids = pgrep
          .stdout
          .toString()
          .split('\n')
          .filter(x => x)

    const subPids = pids.map(findChildren)
    return [].concat.apply(pids, subPids)
}



const pid = process.argv[2]
if(pid === undefined) {
    console.error(`Usage: ${process.argv[1]} <pid>`)
    process.exit(1)
}


findChildren(pid).map(pid => {
    const command = ChildProcess.spawnSync('ps', ['-o', 'command=', pid]).stdout.toString().trim()
    const exec = command.split(/\s/)[0]
    return {pid: parseInt(pid), exec, command}
})
    .map(proc => {
        console.log(proc)
    })